This invention relates to an improved pleated blind and more particularly but not exclusively to pleated blinds for use with inclined openings.
A pleated blind is normally arranged so that its fabric is folded in a concertina fashion between a top rail and a bottom rail. Conventionally, the pleated blind fabric is provided with holes through which a guide cable or rod can pass so t hat when the blind is mounted with its bottom rail at an angle to its top rail, it is maintained generally planar. That is to say, the blind fabric is prevented from sagging or bowing between the two rails. One problem with providing holes in the blind fabric is that the holes weaken the fabric material which can lead to fraying of the material around the holes.
A further problem is that blinds, and in particular triangular or circular blinds, often require several such guide cables or rods. This in turn necessitates that the blind fabric is provided with numerous sets of holes such that each guide rod or cable can pass through a respective set of holes. The provision of a large number of holes in the blind fabric reduces the effectiveness of the blind at cutting out or mitigating the amount of light which is allowed to pass through it. Thus, the holes in conventional blinds have a deleterious effect on the performance of the blind.
Furthermore, blinds having numerous holes therethrough have reduced aesthetic appeal to a user or prospective purchaser.
It would be advantageous to provide a pleated blind which overcomes or ameliorates at least some of the above-noted problems.
According to a first aspect of the present invention, there is provided a pleated blind including two rails and having arranged therebetween a flexible sheet element having a plurality of folds such that the flexible sheet element can be folded between the rails when they are displaced towards one another, and a plurality of support members attached to the sheet element, each of the support members being a one-piece construction including an engagement portion slidably engageable with a fixed guide element arranged transversely to the rails and as a connecting portion for attaching the support member to the flexible sheet, whereby the sheet element is supportable by the support element via the support members.
The provision of a blind including the flexible sheet element and the support members secured thereto obviates a need to provide the flexible sheet element with a plurality of holes through the pleats. This in turn reduces the risk of the flexible sheet element fraying and also increases the efficiency of the blind regarding its light transmission characteristics i.e. the amount of light the blind prevents or restricts passing therethrough. Additionally, in use, the support members are substantially invisible to the naked eye. This dramatically improves the aesthetic appeal of the blinds.
In a preferred embodiment, each support member is releasably secured to the sheet element substantially at a respective fold. More preferably, the folds to which the support members are attached are such that the portions of the sheet element which define the fold all project or extend in the same direction. In this arrangement, the engagement portions for the support members all lie in generally the same plane.
The engagement portion of the support member may comprise a loop or eye through which the support element may pass such that the eye or loop is slidably connectable to the guide element. The support member further includes a connecting portion extending from the engagement portion. The connecting portion more preferably is a T-shaped portion.
The support member is secured to the sheet element via the connection portion. This is desirably achieved by xe2x80x9cpunchingxe2x80x9d or urging the connecting portion through the sheet element such that a first part of the connecting portion (e.g. the shaft of a T-shaped connecting portion) extends through the sheet and a second part of the connecting portion (e.g. the cross bar of the T-shaped connecting portion) engages the front surface of the sheet element and thus resists removal of the support member from the sheet element. By front surface it is meant the surface of the sheet element which is furthest from the engagement portion of the support member.
Where a T-shaped connecting portion is provided, the cross bar of the T preferably includes flexible resilient arms. This makes it easier to secure the support member to the flexible sheet element.
Thus, when using a T-shaped connecting portion, the cross bar of the T is positioned adjacent to a surface of the flexible sheet (the rear surface). A force is then applied to the support member to urge it through the flexible sheet. The portion of the shaft to which the cross bar is connected penetrates the flexible sheet. The flexible arms are engaged by the sheet element and contrarotate about the shaft until they lie substantially parallel thereto. This configuration of the connecting portion permits it to pass through the sheet element with relatively little resistance. Once the arms of the cross bar are no longer engaged by the sheet element, they snap or spring back to their original configuration, i.e. perpendicular to the shaft. The connecting portion thus releasably secures the support member to the flexible sheet as the resilience of the arms of the cross bar resist removal of the connecting portion from the flexible sheet.
By punching or forcing the connection portion of the support member through the sheet element, a relatively small hole is made through the sheet element (i.e. the hole has a diameter which is only fractionally larger than the diameter of the first part of the connecting portion). This hole has a negligible effect on the structural integrity or strength of the sheet element. For example, where the sheet element comprises woven fabric, the act of punching the connecting portion of the support member through it merely results in a realignment of the warp and weft strands of the fabric; it does not typically result in the strands being severed. Thus, as the strands are maintained intact, the structural integrity or strength of the woven fabric remains unchanged. By xe2x80x9cstructural integrityxe2x80x9d, it is meant the ability of the sheet element to resist tearing, fraying or other actions that result in damage to the sheet element.
Even if the sheet element is a non-woven sheet-like material, the relatively small hole made therethrough by the connecting portion would have a negligible affect on the inherent strength or structural integrity of the sheet element. Accordingly, the sheet element is considerably less likely to fray around the hole made by the connecting portion of the support member.
Moreover, as the hole in the sheet element made by punching the connecting portion of the support member through it has a diameter substantially the same as the diameter of the shaft of the connecting portion, very little light can pass through the hole. Thus, the light restricting or suppressing ability of the blind is substantially not affected.
If, as in a preferred embodiment, the cross-bar of the connecting portion is either transparent or coloured a similar colour or tone as the colour or tone of the sheet element, the cross bar becomes generally invisible to the naked eye when the blind is in use. This results in the blind effectively having no visible means of support which in turn increases the aesthetic appeal of the blind.
The guide element with which the or each support member may be engaged is typically a cable under tension or a rod. That is to say, the guide element is preferably a rigid member. Moreover, more than one guide element may be used to support the flexible sheet element of the blind. Accordingly, the pleated blind may include a plurality of sets of support members, the support members is of each set being arranged, e.g. in a linear configuration, so that each set of support members may slideably engage a respective guide element. In a preferred embodiment, the or each guide element is fixed at one end thereof to one of the rails of the blind and at the other end thereof to a support surface outside of the blind. The other of the rails of the blind is provided with one or more apertures through which the or each guide elements may pass such that the other rail is slidably connectable to the guide element.
Preferably, the blind further includes a flexible being secured to the sheet element preferably by the connecting portions of at least some and more preferably all of the support members such that the unfolding of the sheet element is constrained by the connecting tape to a pre-defined maximum spacing between adjacent support members.
The connecting tape may be secured flexibly to the sheet element by the connecting portions of the support members so that some play is possible. This arrangement permits the flexible connecting tape to move and fold more freely during opening or closing of the blind. This in turn permits the sheet element to fold and move more freely. Desirably, the first part of the connecting portion, for example the shaft of the xe2x80x9cTxe2x80x9d where a T-shaped connecting portion is provided, passes through the sheet element and extends a short distance from both surfaces of the sheet element. Accordingly, the length of the first part of the connecting portion substantially determines the distance the connecting portion may extend from either surface of the sheet element. The amount of play is determined by this length of the first part of the connecting portion; the greater this length, the more play will be present.
Advantageously the or each flexible connecting tape is a ribbon or similar thin strip of material and the attachment points for securement of the flexible sheet element to the ribbon are equidistantly spaced along the ribbon length such that the folds will be similarly equidistantly constrained.
An embodiment of the invention will now be described by way of example only with reference to the accompany drawings in which: